1. Field of Invention
The invention generally relates to a calculating instrument and method therefor and in particular the invention relates to a hand-held calculating and method therefor instrument having a writing unit.
2. Description of the Prior Art
The prior art calculating instrument includes a lower disk having numerals on one face and an upper disk having a window and being rotatable about a connecting pin relative to the lower disk.
One problem with the prior art calculating instrument is the difficulty of operating the calculating instrument and immediately thereafter writing down a calculated numeral.